package com.src;

import android.graphics.Camera;
import android.graphics.Matrix;
import android.view.animation.Animation;
import android.view.animation.Transformation;
import com.src.R;
/** 
 * An animation that rotates the view on the Y axis between two specified angles. 
 * This animation also adds a translation on the Z axis (depth) to improve the effect. 
 */  
public class Rotate3dAnimation extends Animation {  
    private final float mFromDegrees;  
    private final float mToDegrees;  
    private final float mCenterX;  
    private final float mCenterY;  
    private final float mDepthZ;  
    private final boolean mReverse;  
    private Camera mCamera;  
  
    /** 
     * Creates a new 3D rotation on the Y axis. The rotation is defined by its 
     * start angle and its end angle. Both angles are in degrees. The rotation 
     * is performed around a center point on the 2D space, definied by a pair 
     * of X and Y coordinates, called centerX and centerY. When the animation 
     * starts, a translation on the Z axis (depth) is performed. The length 
     * of the translation can be specified, as well as whether the translation 
     * should be reversed in time. 
     * 
     * @param fromDegrees the start angle of the 3D rotation 
     * @param toDegrees the end angle of the 3D rotation 
     * @param centerX the X center of the 3D rotation 
     * @param centerY the Y center of the 3D rotation 
     * @param reverse true if the translation should be reversed, false otherwise 
     */  
    public Rotate3dAnimation(float fromDegrees, float toDegrees,  
            float centerX, float centerY, float depthZ, boolean reverse) {  
        mFromDegrees = fromDegrees;  
        mToDegrees = toDegrees;  
        mCenterX = centerX;  
        mCenterY = centerY;  
        mDepthZ = depthZ;  
        mReverse = reverse;  
    }  
  
    @Override  
    public void initialize(int width, int height, int parentWidth, int parentHeight) {  
        super.initialize(width, height, parentWidth, parentHeight);  
        mCamera = new Camera();  
    }  
  
    @Override  
    protected void applyTransformation(float interpolatedTime, Transformation t) {  
        final float fromDegrees = mFromDegrees;  
        float degrees = fromDegrees + ((mToDegrees - fromDegrees) * interpolatedTime);  
  
        final float centerX = mCenterX;  
        final float centerY = mCenterY;  
        final Camera camera = mCamera;  
  
        final Matrix matrix = t.getMatrix();  
  
        camera.save();  
        if (mReverse) {  
            camera.translate(0.0f, 0.0f, mDepthZ * interpolatedTime);  
        } else {  
            camera.translate(0.0f, 0.0f, mDepthZ * (1.0f - interpolatedTime));  
        }  
        camera.rotateY(degrees);  
        camera.getMatrix(matrix);  
        camera.restore();  
  
        matrix.preTranslate(-centerX, -centerY);  
        matrix.postTranslate(centerX, centerY);  
    }  
}  